A recent Washington Post story was headlined: "Why Herman Cain Can Win."

Cain is riding high. He is hiring more staffers. He is the darling of polls and pressrooms and political talk shows. But if the past is any indicator of the future, after raising Cain, the country could start razzing Cain — at any moment.

It's a pattern that plays out over and over again. One candidate sells like hotcakes for a while, then goes cold as a freezer-burned waffle. The electorate gorges on a politician like he's an all-you-can-eat buffet, then disgorges just as quickly. The public gobbles up candidates like candy corn, then spits them out.

So far the 2012 presidential election is seemingly one endless night of bingeing and purging. And one must ask: Has politics become a national eating disorder?

Flavor Of The Week

Sarah Palin was out front at first, then she fell behind. Michele Bachmann was the favorite, then she faded away. Rick Perry rose to prominence, then fell out of grace. So far Mitt Romney and Ron Paul have avoided the flash-in-the-pan attention — which could turn out to be beneficial.

For the time being, though, Herman Cain has the spotlight. He believes his success will continue. "There's a difference between the flavor of the week and Haagen-Dazs Black Walnut, because it tastes good all the time," Cain said to reporters recently. "Call me Haagen-Dazs Black Walnut."

But Eugene Robinson writes this about Cain in The Washington Post: "Enjoy the flavor of the week while you can. Ice cream does melt."

Former Gov. Bob Ehrlich of Maryland says that the flavor-of-the-week syndrome is the function of two elements. The first is that "disproportionate attention is always given to the party out of power — particularly when a large and diverse field is chasing a vulnerable incumbent."

Simply put, Ehrlich says, "the unknown — [the] GOP nominee — is more entertaining than the known — President Obama — in the eyes of the casual observer. "

The second element, he says, is that "today's real time social media tools have expanded the scope and depth of the daily news cycle. Real or perceived misstatements, misdeeds and scandals carry more impact. As a result, candidates — particularly those who lack a reservoir of money and name identification — tend to come and go with more frequency."

This time around they are coming and going like yo-yos.

'Cain Mutiny'?

Who knows? Cain may buck the trend and stay on top until the convention. But even as he basks in the glow of good numbers, partial purging has begun.

By fellow candidates: At the debate, Jon Huntsman dissed Cain's 9-9-9 economic plan, saying he thought "it was the price of a pizza when I first heard it." Rick Santorum criticized Cain's call for a national sales tax. Michele Bachmann implied that 9-9-9 turned upside down is 6-6-6, the mark of the devil.

By the media: Walter Shapiro on The New Republic site called the candidates' criticisms of Cain the "Cain Mutiny" and said the tide turning against Cain is "as inevitable as the Iowa Caucuses moving into the Christmas season."

And on Wednesday morning, Ben Howe on the Red State website observed, "I've written on Rick Perry before and expressed that he is a candidate that I can support. I'd also previously expressed an interest in Sarah Palin, Chris Christie and Herman Cain. Sarah and Chris aren't running obviously, and last night I got a deeper insight into who Herman Cain is. I find myself disappointed and concerned."

By voters: "I think Cain took major damage last night," wrote a commenter on the Free Republic website the morning after the debate. "He's not done for, but it took 3 debates to destroy Perry, and it will probably take 3 to destroy Cain. It's a shame that Bachmann and Santorum can't use their sharp tongues to destroy Romney before they exit the stage forever."

When it comes to the 2012 election season, the vicious vicissitudes may help the smooth-striding Romney. At the same time, observed Al Hunt on Bloomberg Surveillance, "it is a little bit disturbing news for Mitt Romney in the sense that he is steady. He stays right around 23 percent, 25 percent. But when the others fall, he doesn't rise."

And when it comes time for Romney to shine, there may be a problem, says Craig Shirley, a Ronald Reagan biographer and consultant to conservatives. "For many, Romney is ideologically and culturally all wrong for the modern Republicans," Shirley says. "To the Reaganite Tea Party majority of the GOP, he is too Northeast, too rich, too liberal, too much of a Reagan-basher."

So who's next on the binge-purge political menu? Writing for Forbes.com, T.J. Walker observed that Romney gave a strong front-runner performance at this week's debate "and left pretty much untouched by his opponents."

But Walker added, with a certain resonance for the binge-purge theorists: "Meanwhile, Rick Santorum came off as a much more likable candidate in this round-table setting than he ever has before."